Air-cylinder.



J. J. OLSON.

AIR CYLINDER.

APPLIOATION FILED 1330.24 1910.

1,050,287, 7 Patented Jan. 14,1913.

A TTORNE Y JOHN J. OLSON, OF SUPERIOR, WISGONSIN.

AIR-CYLINDER.

Specification of Letters Patent.

Patented Jan. 14,1913.

Application filed December 24, 1910. Serial No. 599,170.

'b all whom it may concern Be it known that I, J OHN J. OLSON, a citizen of the United States, residing at Superior, in the county of Douglas and State of lVisconsin, have invented certain new and useful Improvements in Air-Cylinders, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates to improvements 1n air cylinders, and pertains more particularly to means for cushioning the return stroke of the piston.

The object of my invention is to provide an automatic cushioning means for the piston of an air cylinder to prevent the piston from coming in contact with the upper end of the cylinder on the return stroke and in which the said cushioning means is the air pressure of the cylinder.

Another object of my invention is to provide a cushioning means which is controlled by the piston within the cylinder, whereby it is impossible for the piston to engage the end of the cylinder on its return stroke.

A still further object of my invention is to provide piston packing rings which will more snugly engage the cylinders after they have become slightly worn.

In the accompanying drawing the figure is a broken vertical section of a cylinder equipped with my improved appliances, showing one of the packing rings in'section and another in elevation.

Referring now to the drawings, 1 represents the cylinder formed preferably with the removable lower end, 2 and the solid upper end 3, through which latter the piston rod l: operates, it being surrounded by a suitable stuiiing gland 5 to prevent air leakage.

An elongated bell-shaped piston 6 is attached to the piston-rod t and operates with in the cylinder 1, it being somewhat smaller in diameter than the cylinder and operatively engages with the interior of the same by means of the piston ring 7 of which there may be one or more as desired.

Aseat 8 is formed upon the outer wall of the piston 6 having a concaved outer face 9, in which the ring 7 rests, it being formed with the convex portion 10 to snugly fit therein, its outer face 11 being smooth and flat to engage the inner wall of the cylinder 1. The ends of the rings 7 are cut obliquely as is common in such devices. By this form of ring it is evident that the convex. seat constantly exerts a slight outward thrust of the ring when moving up or down in the cylinder, thus materially assisting in maintaining a tight joint therebetween.

A passage 12 is formed longitudinally the piston rod communicating with the interior of the piston 6 through which air is admitted to the cylinder and the piston operated therein. The upper end of the passage 12 may communicate with the air supply in any convenient manner, depending upon the form of attachment of the piston rod, this to be in keeping with the work the cylinder is required to perform. A passage or port 13 is also formed within the piston rod 4, the lower end 14 of which extends laterally through the outer wall of the piston rod a short distance above the upper end of the piston 6, and communicates with the interior of the cylinder, when the piston is extended within the cylinder, but is shut off by the wall of the cylinder as the piston reaches the uppermost limit of its stroke. The upper end 15 of the port 13 extends laterally through the outer wall of the piston rod and is so positioned as to communicate at all times with the outer air. This port 13 is for the purpose of admitting air to the cylinder above the piston 6, as the latter is extended within the cylinder and thus prevents a vacuum forming above the piston and this port is closed as above described just previous to the piston reaching the limit of its return stroke.

A valve housing 16 is mounted within the upper end 3 of the cylinder 1, it having therein the flat valve 17 mounted upon the stem 18 which latter extends within the cylinder 1 in such a manner as to engage the upper wall of the piston as it nears the upper limit of its stroke. The valve 17 when closed rests upon a suitable seat 19.

A pipe 20 communicates between the valve housing 16 above the valve 17 and the lowermost end of the cylinder 1, thus a cortinuous pressure of air is maintained above the valve 17, keeping it closed-at all times when a pressure of air is within the cylinder 1 for the purpose of keeping the piston up, except when it is at or about the limit of its upward stroke. WVhen the piston 6 ap .proaches the limit of its upward stroke, the

upper wall thereof will impinge against the valve stem 18 and thrust it upward, which will open the valve 17, thus admitting air to the cylinder above the piston 6, and this air 2 rorsaasv being under the same pressure as that at the opposite end of the piston will immedlately equalize the thrust at both ends thereof and arrest the upward travel of the piston and act as a cushioning means. It is assumed that pressure other than that associated with the air operating pressure is applied either constantly or intermittently to the piston rod 4 in an eiiort to keep it extended within the cylinder 1, and such pressure might come from the weight of a vehicle body in the event of the cylinder being used for cushioning means therefor, or if the cylinder was used as a door cushion, the pressure would be applied to the closing of the door and there are various other devices to which my automatically air cushioned cylinder could be applied for which reason I have not shown any particular connection as that does not constitute part of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A device of the character described, comprising an air cylinder having a passage in communication with the lower end of the cylinder and extending around and in communication with the upper end of the cylinder, a valve controlling the communication of the upper end oi the cylinder, a piston operating within the cylinder and adapted to open said valve, a piston rod carried by the piston and having a passage therethrough adapted to supply steam to the cylinder below the piston, substantially as shown.

2. A device of the character described, comprising an air cylinder, a piston therein, a piston. rod carried by the piston and extending through the cylinder and having a fluid passage therethrough, the said piston rod having a passage therethrough and having laterally turned ends, a pipe connected to the lower end of the cylinder and in communication with the upper end of the cylinder, a valve controlling the communication at the upper end of the cylinder and means whereby the said valve is operated by the piston.

3. A device of the character described, comprising a cylinder, a piston therein, a piston rod carried by the piston and extending through the cylinder, and having a fluid passage therethrough, the said piston having a passage therethrough and having laterally turned ends and automatic means connecting the ends of the cylinder for cushioning the upward stroke of the piston.

4:. A device of the character described, comprising a cylinder, a piston operating within the cylinder, a piston rod carried by the piston and having a fluid passage therethrough and through the piston, said piston having a passage having laterally turned ends communicating with the sides, a valve housing in communication with the upper end of the cylinder, a valve closing said communication, a valve stem carried by the valve and extending within the cylinder, and a pipe connecting the upper end of the chamber and the lower end of the cylinder.

5. A device of the character described, comprising a cylinder, a piston therein, a piston rod carried by the piston and extending through the cylinder, the said piston rod having a passage therethrough and having laterally turned ends, and automatic means connecting the ends of the cylinder for cushioning the upward stroke of the piston.

6. A device of the character described, comprising a cylinder, a piston operating within, a piston rod carried by the piston and extending through the cylinder, said piston rod having a passage having laterally turned ends communicating with the side, a valve housing in communication with the upper end of the cylinder, a valve closing said communication, a valve stem carried by the valve and extending within the cylinder, and a pipe connecting the upper end of the chamber and the lower end of the cylinder.

7. A device of the character described, comprising a cylinder, a piston operating within the cylinder, a piston rod carried by the piston and having a fluid passage there through and through the piston, said piston rod having a passage having laterally turned ends communicating with the sides, a valve housing in communication with the upper end of the cylinder, a valve closing the communication, a valve stem carried by the valve and extending within the cylinder, a pipe connecting the upper end of the chamber and the lower end of the cylinder, and means carried by the chamber whereby the valve may be removed.

In testimony whereof I hereunto aiiix my signature in the presence of two witnesses.

JOHN J. OLSON Witnesses:

7M. M. GRAVATT, S. Geo. STEVENS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. U. 

